Name ........................................................................................................................
Form ....................................
SCIENCE
YEAR 8 REVISION GUIDE—CHEMISTRY SECTION
Science Department
This Revision Guide will be generated as the year progresses. Each topic is
covered with both ‘key fact’ sheets, a question sheet and a suggested revision
method.
The question sheet is designed to test your revision of the key facts and see if
the information has sunk in. Just answering the questions is not an effective
revision method.
You will be given a set of sheets for each topic as you cover them in lessons.
The revision sheets will help you to revise for the end of unit test and your
school entrance exams at the end of year 8.
You will be given one hard copy to store in this folder but replacements can
be found online in the Student and Parent Portal section of the school
website. You are allowed to print as many copies as you like for your own
use.
We hope that they will be useful.
Good Luck
The Science Department
Elements, Compounds and Mixtures
Element
= Substance consisting of one type of atom
Compound = Substance consisting of two or more different elements chemically combined
Mixture
= Substance containing two or more elements or compounds that
have not been chemically joined.
Molecule = A groups of atoms chemically joined e.g. water H2O, oxygen O2
The Atom
Consists of three different units. Electrons (negatively charge and
whizzing around the outside), Protons (Positively charged and in the
nucleus.) and Neutrons (no charge and in nucleus).
Atoms combine to form compounds.
Particle Theory
As particles are heated they gain kinetic energy. As they are cooled they lose kinetic energy.
Elements
Elements form the periodic table.
Metals


Metal Oxides are BASIC and SOLID
For example magnesium + oxygen
Non-metal Oxides are ACIDIC and GASES
For example carbon + oxygen
Non-metals
Name
Symbol
Hydrogen
H
Carbon
C
Sulphur
S
Iron
Fe
Copper
Cu
Sodium
Na
Oxygen
O
Nitrogen
N
Calcium
Ca
Helium
He
Magnesium
Mg
Potassium
K
magnesium oxide
carbon dioxide
Compounds


Compounds are formed when two or more elements combine.
Compounds have different properties to the elements that combine to make them.
Naming Compounds
1.
2.
–ide = Two elements joined together e.g. Iron + Sulphur
Iron Sulphide
–ate = More than two elements joined together with oxygen being one of them
e.g. Copper + Sulphur + Oxygen
Copper Sulphate
Class practical: Iron + Sulphur
Iron Sulphide
You need to recognise this reaction. It shows that a new substance is formed.
Before reaction Iron is magnetic. Iron Sulphide is not
and therefore proves a new substance has been formed.
Look at the observations made during this reaction.
Chemical Symbols
Chemical symbols are used to represent compounds. The numbers relate to how many atoms there
are in the compound.
Water has two Hydrogen atoms
H2O
and one Oxygen atom
Conservation of mass – The mass of the reactants equals the mass of the products. For example,
Magnesium gets heavier when heated in air because it chemically combines with oxygen to form
Magnesium oxide (Mg
MgO).
Mixtures



Mixtures are two elements or compounds that are together but not chemically joined.
Dissolving is a good way to form a mixture.
Mixtures can be easily separated (See separating substances section when complete)
Possible Revision Method—Summary Cards

Summary Cards contain the most important details of a topic. You should try to create
a summary of the information, including key words, concepts and diagrams.
Summary Topic: Elements, Compounds and Mixtures
Card No. __________
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1.
What three particles combine to form an atom?
2.
What is the name given to the negatively charged particle in an atom?
3.
Define an element.
4.
Define a compound.
5.
Define a mixture.
6.
Draw diagrams to represent the particles in each of the states of matter below.
Liquid
Solid
Gas
7.
Where do you find non-metals on the periodic table?
8.
Copper + Oxygen
9.
Copper + Sulphur + Oxygen
10.
Iron + Sulphur
11.
How can you tell that a reaction is occurring (or has occurred) between Iron + Sulphur in
the production of Iron Sulphide? Give two reasons
12.
How many Carbon atoms are there in a molecule of Glucose?
___________________
____________________
___________________
C6H12O6
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide





Atoms and Elements
Periodic Table
Compounds
Naming Compounds
Mixtures
pg. 35
pg. 36
pg. 37
pg. 38
pg. 39
Making and Testing Gases & Gases in the Air
Hydrogen
Making Hydrogen
METAL + ACID
SALT + HYDROGEN
MASH
Testing for Hydrogen
Using a lit splint the hydrogen should ignite with a
squeaky pop.
Oxygen
Making Oxygen
Thermally decompose (heat) potassium permanganate
Testing for Oxygen
Using a glowing splint plunge into oxygen and it should relight.
Carbon Dioxide
Making Carbon Dioxide
METAL CARBONATE + ACID
WATER + SALT + CARBON DIOXIDE
MCAWSCD
Testing for Carbon Dioxide
Bubble carbon dioxide through limewater. Limewater turns
milky white.
Collecting Gas over water

If a gas needs to be collected it should be done over water as shown in diagram below. (Learn the diagram!)
Gases in the Air


Air is a mixture of gases
It consists of different quantities of a variety of different gases
Gas
Nitrogen
Oxygen
Carbon Dioxide
Argon and other
trace gases
Percentage of
Air
78%
21%
0.03%
Trace amounts
To prove the percentage of oxygen you can use the set up shown below. Heat the copper
filings between the syringes to form copper oxide and remove oxygen from the air within the
syringes. The syringe should read 100ml at the beginning and 79ml at the end thus showing oxygen is 21% of air.
HEAT
Possible Revision Method—Review Cards (Flash Cards)


Review Cards pose questions with long answers or facts on the back.
Flash Cards can be used to learn key words or definitions
SCIENCE: Making and Testing Gases
Question
Answer(s)
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1.
How is Hydrogen made in a lab?
2.
How do you test for Hydrogen?
3.
How is Oxygen made in a lab?
4.
Do you use a lit splint or glowing splint to test for oxygen?
5.
What substance is used to test for carbon dioxide?
6.
What change is seen in this substance if carbon dioxide is present?
7.
Write the word equation for the production of carbon dioxide.
8.
Write the word equation for the production of hydrogen.
9.
Draw the diagram for the collection of gas over water.
10.
Why does gas rise to the top of the test tube when being collected over water?
11.
What is the percentage of Nitrogen in the atmosphere?
12.
If 100cm3 of Air is passed over copper filings which are being heated. After several
minutes what will be the volume of air?
13.
Why?
Fuels
Fuels react with oxygen to release energy. Most fuels contain hydrocarbons.
These are compounds of hydrogen and carbon only.
Complete Combustion:
Complete combustion releases more energy than
incomplete combustion. It requires a plentiful supply
of air so that the elements in the fuel react fully with
oxygen.
The general equation for complete combustion is:
hydrocarbon + oxygen
carbon dioxide + water
Incomplete Combustion:
Incomplete combustion occurs when the supply of air or oxygen is poor, resulting in carbon
monoxide being produced rather than carbon dioxide and producing some carbon (soot) which
has not be oxidised.
The general equation for incomplete combustion is:
hydrocarbon + oxygen
carbon monoxide + water
or
Hydrocarbon + oxygen
carbon + water
The Bunsen Burner
Air hole open
When the air
hole is open, air
is drawn into the
chimney, where
it mixes with the
natural gas. This
ensures complete
combustion.
Air hole closed
When the air hole is closed
the natural gas can only mix
with air at the mouth of the
chimney. Incomplete
combustion occurs as a
result. A yellow flame is
produced, which transfers
less heat energy than the
blue flame.
Questions
If you have revised the previous sheets effectively you should be able to answer the following questions without difficulty.
1.
How can you test that carbon dioxide gas was produced?
2.
What is a test to determine that water is present?
Acids, Alkalis and Neutralisation
Acids





Have a low pH
Have a sour taste (tartaric acid used in toxic waste sweets!!)
Contain Hydrogen and are used to make Hydrogen in reactions with metals.
Make Carbon Dioxide in reactions with carbonates.
Can react to produce salts – Hydrochloric Acid  Chloride Salts, Nitric acid  Nitrate
Salts, Sulphuric Acid  Sulphate Salts etc.
Alkalis




Have a high pH
Soapy texture (often used in cleaning fluids)
Alkalis are soluble bases (bases which have dissolved)
All alkalis are bases but not all bases are alkalis.
Bases



Substances which can neutralise an acid.
When dissolved in water to form a solution are called alkalis
Usually metal oxides, hydroxides or carbonates e.g. Magnesium Oxide, Sodium
Hydroxide.
The pH Scale
Used to help identify the strength of an acid or base/alkali.
Universal Indicator is used to help show the pH by checking the colour
it turns against the colour chart.
If an acid is diluted its pH does not change significantly.
Neutralisation
When acids and alkalis are combined to form salts.
The salt contains the metal from the alkali and part of the acid molecule.
eg Sodium Hydroxide + Hydrochloric Acid  Sodium Chloride + Water
The salt depends on the type of acid e.g. sulphuric acid forms
sulphate salts.
ACID + ALKALI
SALT + WATER
The Reactions of Acids with Alkalis, Bases, Metal Carbonates and Metals
The Rules





Bases are metal oxides or metal hydroxides, e.g. iron oxide and calcium hydroxide.
Alkalis are bases which dissolve in water. They are always metal hydroxides, e.g.
potassium
hydroxide and sodium hydroxide.
Metals all conduct electricity. Lots of them have names ending in ‘-ium’ although
there are a few
non-metals which also end in ‘-ium’. They include metals with common names like
copper, lead and aluminium.
Metal Carbonates are all metals combined with carbonate groups, e.g. copper
carbonate, potassium carbonate and iron carbonate. They are also classified as bases
because they neutralise acids, but they react with acids in a different way to metal
oxides and metal hydroxides.
Acids all contain hydrogen. The three we need to know are hydrochloric acid,
sulphuric acid and nitric acid.
Hydrochloric acid reacts to form chloride salts
Sulphuric acid reacts to form sulphate salts
Nitric acid reacts to form nitrate salts.
The Rules II
Base + Acid  Water + Salt (BAWS)
Acid + Alkali  Water + Salt (AAWS)
Metal + Acid  Salt + Hydrogen (MASH)
Metal Carbonate + Acid  Water + Salt + Carbon Dioxide (MCAWSCD)

A salt is a metal sulphate, metal chloride or metal nitrate.
Hydrochloric acid makes chloride salts
Sulphuric acid makes sulphate salts
Nitric acid makes nitrate salts
Phosphoric acid makes phosphate salts
Neutralisation Reactions
1.
Sulphuric Acid + Copper oxide 
2.
Nitric Acid + Iron carbonate 
3.
Hydrochloric acid + sodium hydroxide 
4.
Sulphuric acid + Zinc 
5.
Acetic acid + aluminium 
6.
_____________ + ____________  lead nitrate + carbon dioxide + water
7.
______________ + Magnesium  Magnesium chloride + _____________
8.
Nitric acid + ____________  Calcium __________ + water
9.
Zinc oxide + Nitric acid 
10.
Magnesium hydroxide + sulphuric acid 
11.
Copper + hydrochloric acid 
Possible Revision Method—Review Cards (Flash Cards)


Review Cards pose questions with long answers or facts on the back.
Flash Cards can be used to learn key words or definitions
SCIENCE: Neutralisation Salt Names
Question
Answer(s)
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1.
Is an acid’s pH low or high?
2.
What chemical element do all acids contain?
3.
Name a household acid.
4.
What chemical compound do acids always produce in the reactions you have learnt?
5.
What acid produces chloride salts?
6.
What acid produces sulphate salts?
7.
What acid produces nitrate salts?
8.
What is an alkali?
9.
Is an alkali’s pH high or low?
10.
Name a household alkali.
11.
Give two examples of bases.
12.
What is the pH scale used for?
13.
How do you find the pH of a chemical? (include all detail!) [3 marks]
14.
Does an acid’s pH change much if water is added to it?
15.
What determines which salt is produced in a neutralisation reaction?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide




Acids and Alkalis
Neutralisation Reactions
Reaction of Metals with Acids
Reaction of Oxides with Acids
pg. 52
pg. 53
pg. 55
pg. 56
Particle and Kinetic Theory & Waters and Solutions
Particle and Kinetic Theory


Particle theory states that mass exists in particles
Kinetic theory revolves around the particles moving differently at different temperatures or
energy states.




Fixed shape
Fixed Volume
Particles Vibrate
Doesn’t flow
Changes of state
 Shape of container
 Fixed Volume
 Particles move a
little more than
solid but still
touching
 Flows
 Shape of container
 No Fixed Volume
 Particles move
quickly
 Flows
Water and Solutions
The heating curve of water as shown on a graph. You must learn what the plateaus on the graph represent.


If you add salt or other minerals to water it lowers the freezing point (takes it below 0oC) and
raises the boiling point (takes it above 100oC)
This is why salt is put on roads to de-ice and in boiling water to cook pasta quicker.
Tests for Water
Hydrated = Contains water within the chemical structure
Anhydrous = Without water in the chemical structure
Anhydrous Copper Sulphate goes from white  blue when water is added. It turns into
hydrated copper sulphate.
Anhydrous Cobalt Chloride goes from blue  pink when water is added. It form hydrated cobalt
chloride.
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1.
Draw diagrams to represent the particles of solids, liquids and gases.
2.
Using kinetic theory describe what happens when a solid melts?
3.
Using particle theory explain what the particles of a gas are like?
4.
Using kinetic theory explain what happens when a gas condenses
5.
What is the energy transfer that occurs during melting?
6.
What is the process called when a gas turns directly into a solid?
7.
Describe, using the most scientific language possible, what happens when a bar of dairy
milk is left in the midday sun for an hour and then put in the fridge overnight.
8.
Draw the heating curve graph for water and label each plateau appropriately.
9.
What does the term hydrated mean?
10.
Describe the colour changes when anhydrous copper sulphate is exposed to water?
11.
Describe the colour change when a moist piece of cobalt chloride paper is put on a hot
plate?
12.
Why does road grit contain rock salt?
13.
Why does Gordon Ramsay recommend that you put salt in the water when boiling
potatoes?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide




Solids, Liquids and Gases
Particle Theory
More Particle Theory
Movement of Particles
pg. 31
pg. 32
pg. 33
pg. 75
Possible Revision Method—Videos, Animation or Presentation


Make a video or animation to explain a concept.
Create a Presentation and then present to your family or peers to explain the concept.
Create an animation to explain the changes of state using particle theory.
Using tablet apps.
Separating Mixtures
Solution:
Mixture:
Dissolving:
Soluble:
Insoluble:
Saturation:
Sedimentation:
Suspension:
Solute:
Solvent:

When a solute combines with a solvent. Transparent in appearance
When two substances are put together but do not chemically combine
When a solution is formed. An example of a mixture.
Substance can dissolve
Substance cannot dissolve
When a solvent has no further space for a solute to dissolve at that
particular temperature
When an insoluble solid sits at the bottom of a liquid
When an insoluble solute sits a top the solvent.
Solid in a solution.
Liquid in a solution.
Because substances in mixtures are not chemically combined they can be separated easily.
Separating Miscible and immiscible liquids




Immiscible liquids are liquids which do not mix together.
e.g. Water and Oil
Immiscible liquids are separated with a separating funnel.
Miscible liquids are liquids which have mixed together
e.g. Alcohol and Water
Miscible liquids are separated using distillation. The liquid with
the lower boiling point evaporates first and is condensed using a
Liebig condenser before collecting.
Simple Distillation
You need to be able to draw a diagram of simple distillation
Separating Salt from Rock Salt
A three stage process.
1. Rock salt grinded (to increase
surface area making it easier to
dissolve in water) and dissolved
in water to separate soluble salt
from insoluble rock.
2. Solution filtered for further separation of soluble from
insoluble.
3. Solution heated to separate
water and salt
Fractional Distillation
Solubility


The ability of a substance to dissolve and form a solution
Solubility can be affected by the temperature of a solution

Solubility of a substance is usually plotted on a
graph as shown here. As temperature increases
solubility increases.

In some substances solubility increases a lot as
temperature increases, in others the increase is
less
Chromatography


Used to separate substances of different solubilities.
Inks contain miscible liquids of different solubilities. The ink is dissolved in the solvent as
it travels up the chromatography paper. The ink that dissolves the best (most soluble)
travels the furthest.
Most Soluble Ink
Least Soluble Ink
Possible Revision Method—Summary Cards

Summary Cards contain the most important details of a topic. You should try to create
a summary of the information, including key words, concepts and diagrams.
Summary Topic: Separating Mixture Techniques
Include scientific drawings and description on each separating mixture technique.
Card No. __________
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1.
What is a solvent?
2.
What is a solute?
3.
What is a mixture?
4.
What is the appearance of a solution?
5.
What is saturation?
6.
What are miscible liquids?
7.
How are immiscible liquids separated?
8.
What property of miscible liquids enable them to be separated by distillation?
9.
What is the name given to the apparatus used to condense the gas in distillation?
10.
Why is rock salt ground in the first stage of its separation?
11.
Why is the ground rock salt placed into water?
12.
What happens to the solubility of a solution as it is heated?
13.
Using the graph above calculate the solubility of sodium nitrate at 90oC
14.
Using the same graph identify which solution has the highest solubility at 20oC
15.
Using the same graph identify which solution has the highest solubility at 80oC
16.
What is chromatography used to separate?
17.
Where would you find the most soluble ink on a chromatogram? Closest to the starting
point or furthest from the starting point?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide


Mixtures
Separating Mixtures
pg. 39
pg. 40 and pg. 41
Metals and The Reactivity Series
Metals

Found on the periodic table to the left of ‘the stairs’
Properties of Metals





Conducts electricity
Conducts heat
Malleable
Ductile
Shiny (when freshly cut)
Reactivity
Some metals can react with water and most react with acids. How well a metal reacts with another
substance is known as its ‘reactivity’. The Reactivity Series shows the most reactive metals at the
top of the series and least reactive at the bottom.

Some metals react with water to produce Hydrogen gas
e.g. Potassium, Sodium and Calcium

Some metals react with steam and not water e.g.
Magnesium

Some metals do not react with either because they are
too unreactive e.g. Gold and silver. These are used for
building and jewellery e.g. Copper for pipes and Gold
for necklaces.
Those in red are non-metals added
for comparison!
Metals and Acids
Metals react with acids quite readily. When they react they produce Hydrogen gas.
Metal + Acid  Salt + Hydrogen (MASH)
Displacement Reactions


A more reactive metal can react with a less reactive metal to displace it.
A more reactive metal can replace a less reactive metal from its oxide
Magnesium + Copper Oxide  Magnesium Oxide + Copper
Copper Sulphate + Iron  Iron Sulphate + Copper



Displacement reactions can result in large amounts of energy being released
Displacement reactions are used to separate pure metals from their ore (natural state)
Many metals do not exist in pure form in nature because they are reactive. Displacement
can remove them from their natural state.
The Thermit Reaction:
A reaction used many years ago to produce molten iron which was then used to weld
railway line together. Quick and vigorous displacement reaction.
Iron (III) Oxide + Aluminium  Aluminium Oxide + Iron
Rusting


Rust forms when Iron reacts with Oxygen and Water to produce Iron (III) Oxide
Look at the experiment to see how we test to see if Water and Oxygen are needed for
rusting to occur.
Rust Prevention:
1.
2.
3.
4.
Painting – Waterproofs the iron
Oiling – Provides waterproof layer.
Galvanising – Coating Iron in Zinc
Sacrificial protection – Providing a more reactive metal for Water and Oxygen to react
with instead of iron
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1.
Name three properties of metals.
2.
Where on the periodic table are metals found
3.
Which is more reactive: Magnesium or Iron?
4.
Which is less reactive: Sodium or Calcium?
5.
Which is more reactive: Carbon or Hydrogen?
6.
Which metal reacts with steam but not with cold water?
7.
Name two metals that react with cold water?
8.
What is produced when a metal reacts with an acid?
9.
Complete the following displacement reactions:
a.
Iron Oxide + ___________  Magnesium Oxide + __________
b.
Copper Sulphate + Iron  ________ _______________ + _____________
c.
Potassium Oxide + Sodium  ___________ ____________ + _____________
d.
Iron (III) Oxide + Aluminium  ________ _____________ + ____________
e.
________ ________ + ____________  Calcium Oxide + Tin
10.
How can you tell that the reaction between copper sulphate and an iron nail results in Iron
Sulphate and Copper? Look at the diagram carefully.
11.
What two substances are required for rusting to occur?
12.
Name two methods of rust prevention. Explain how they work?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide




Property of Metals
Property of Non-metals
Reactivity Series and Metal Extraction
Displacement Reactions
pg. 42 and pg. 43
pg. 44 and pg. 45
pg. 40
pg. 52
Possible Revision Method—Create a Mnemonic

An mnemonic is a made up rhyme to help you memorise lists of information.
Create an mnemonic to help you memorise the order of metals in the Reactivity Series
Dulwich Prep London
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